Variable resistance auxiliary electrical receptacle for electrical lighting appliances



July 21, 1953 R. A. MCARRON 2,646,489 VARIABLE RESISTANCE AUXILIARY ELECTRICAL RECEPTACLE FOR ELECTRICAL LIGHTING APPLIANCES Filed July 17, 1951 FIGAL.

INVENTOR 120 yer A .Mcflrroiz ATTORNEY Patented July 21, 1953 VARIABLE RESISTANCE AUXILIARY ELEC- TRICAL RECEPTACLE FOR, ELECTRICAL LIGHTING APPLIANCES Roger A. McArron, Somerset, Ohio Application July 17, 1951,Serial No. 237,234

3 Claims.

' The'present'invention'relates to auxiliary electrical receptacles, and has'particular reference to an improved electrical receptacle for electric lighting "appliances which incorporates an electrical resistance element for automatically, controlling the voltage supplied from a source of current to an electrical lighting appliance or fixture in amanner governing the illumination of the lighting appliance or fixture.

'Ihe primary object of the present invention is to provide an auxiliary electrical receptacle with which an electrical lighting appliance or fixture may be connected, and which functions, upon energization of an operating circuit for the lighting fixture or appliance, to initially reduce the voltage supplied to an incandescent lamp carried in the "appliance and to progressively increase such voltage in a manner whereby the electric lighting instrume'ntalityv will be first caused to glow, and. thereafter increase in i1- luminating intensity to substantially its maximum illuminating capacity, to thereby eliminate asudden and intense illumination of the lighting instrumentality upon closure of its operating circult, and at the same time to reduce the detrimental eifects to the filament of the lamp occasioned by 'a sudden surge of current upon closure of the operating circuit for the lighting instrumentality.

It is another object of the invention to provide an auxiliary electrical receptacle which incor-,

porates a resistance element having a negative temperature-resistance coeflicient which is connected in series with the operating terminals of the receptacle in a manner by which an electric lamp or other lighting fixture electrically con :nected with the terminals of the receptacle may, upon energization of its operating circuit, be supplied with a relatively low voltage immediately following energization of the operating circuit, and which thereafter functions to progressively increase the amount of voltage passing to the lighting fixture in a manner to cause the fila- .ment thereof to initially glow in a subdued light and progressively increase in intensity to substantially its maximum candle power output.

Electrical receptacles formed in accordance with the present invention find particular value when used in connection with a lighting appliance to produce a bedroom or bathroom night light, whereby, upon closure of the operating circuit for the lighting fixture, the lamp b ulb will be caused to initially transmit light rays of relatively low intensity and thereafter increase in illumination to prevent harmful and painful 2 shock to the optical nerves of "a' person occupying a previously darkened room, or a person having just awakened from sleep.

For a further andmore detailed understanding of the present invention, and the various additional objects and advantages realized therefrom, reference is tobe had to'the following description and the accompanying drawing, wherein:

Fig. l is a perspective view 'of'an auxili'aryel'ectrical receptacle formed in'accordance with the present invention; d

Fig. 2 is a medial longitudinal vertical sectional view taken through the receptacle;

Fig. a detailed horizontal sectional view taken-along the line 33 of Fig. 2; and

Fig. 4 is a circuit diagram of an electrical lighting circuit incorporating the present auxiliary receptacle. Y f

Referring now to the drawing, the numeral 5 designates generally the present auxiliary resistance-containing electrical receptacle which comprises an outer tubular cylindrical casing 5, the walls of which are perforated substantially throughout its entire area, and which is preferably formed from a high heat conductivity metal, such as copper. Each end of the perforatetasing 6 is formed to provide an annular radially and inwardly projecting rib l, and the end portions of thecasing ii are split longitudinallygas at 8, a distance inwardly from the ends thereof to provide resiliently expansible clamping portions.

Carried in the upper end portion, as viewed in Fig. 2, is a cylindrical end member 9 which is formed from any suitable dielectric material, such as porcelain, or one of the dielectric resins of the phenol formaldehyde type; The upper end member 9 is formed to provide a pair of internal sockets Ill which open outwardly of the member 9 by way of a pair of terminal-receiving slots l I through which the male terminal prongs of an electric lighting appliance, not shown, may be inserted. Extending within the sockets iii, and rigidly carried by the dielectric end member 9, are a pair of spring-type electrical contacts l2 whose separate leg portions define slots in registration with the openings l i of the end member 8/ The bifurcated contacts l2 are arranged so as to be resiliently expanded upon insertion therein of the usual male terminal extensions associated with lighting fixtures.

A similar dielectric end member I3 is carried within the opposite or lower end of thecasing minal prongs 24 which extend outwardly from the lower end of the member It in relatively spaced non-shorting relation and for insertion within the separate female sockets of the usual wall-mounted electrical receptacle, not shown. The male terminals l4 extend completely through the dielectric end member 53 and terminate at their inner ends in angularly related webs l5.

Electrically connecting the right-hand contact 12 with the right-hand male terminal prong l4, as viewed in Fig. 2, is an electrica1 conductor [5 having one end suitably connected with the inner end of the contact I2 and its opposite end connected with the Web l5 of the right-hand terminal M, such as by soldering. The intermediate portion of the conductor I6 is insulated from electrical contact with the outer casing 6 by means of an outer covering l! of dielectric material.

Connected between the opposite or left-hand contact I2 and the male terminal prong I4 is a bank composed of a plurality of cylindrical resistance elements [8 having separate end leads l9 extending through suitably spaced openings formed in a pair of circular spacer disks disposed at either end of the resistance elements [8. The end leads 19 have their outer end extremities wound together into a single manifold conductor 2| which is soldered to the inner end portions of the left-hand contact l2 and terminal prong 14. In this manner, the separate resistance elements I8 are electrically connected in parallel, while the entire bank of resistance element forms a series connection between the left-hand terminal prong l4 and the contact l2. It will be understood, that the spacer disks 28 may be formed from any suitable dielectric material, such as mica, fiber board, or a suitable dielectric resin, and function to maintain the individual resistance elements l8 in relatively spaced relationship and in spaced relation to the inner wall surface of the outer casing 6.

For purposes of assembly, I have found it advantageous to initially assemble the bank of separate resistance elements [3 together with the spacer disks 20 and the wound manifold end extensions 2! to provide a unit, and in assembling the separate elements of the receptacle, the lower manifold 2| of the resistance elements is initially ,c

end of the casing 6 is resiliently snapped over F the inner end of the member l3 and forced downwardly upon the member [3 until the inwardly directed flange engages a peripherally disposed groove 22 formed in the member l3. The upper manifold 2| and the upper end of the conductor 16 are then drawn outwardly through the upper end of the casing 6, and soldered to the respec tive terminals 12 of the upper end member 9, it being understood that the conductor [6 and the end extensions 19 of the resistance elements 18 are of a sufficient length to permit the same to be drawn outwardly of the opposite ends of the casing 6. After soldering of the conductor 16 and manifold 2| to the contacts [2, the upper end member 9 is forced into the upper end of the casing 6 until the inwardly projecting annular rib 7 of the casing lodges within the cooperative groove 22 of the upper member 9. In this manner, the respective end members 9 and 13 are securely locked within the outer Casing 6 to provide a rigid unitary structure containing the resistance elements l8 in spaced non-shorting relationship to the conductor 16.

As previously stated, the resistance elements iii are of a type having a negative temperatureresistance coefficient, whereby the resistance of each element decreases in direct proportion to the heat of the element. In this connection, each of the resistance elements 18 may comprise a resinous or ceramic material having a metallic oxide incorporated therein which, at ordinary temperatures, has a high resistance, but Which decreases in resistance in direct proportion to the heat established within the resistance element through energization of an operating circuit associated therewith.

Fig. 4 of the drawing discloses a circuit diagram embodying the present resistor-type receptacle. In Fig. 4, the reference characters LI and L2 designate the power lines for the ordinary household alternating current circuit which, in the usual manner, is provided with outlet receptacles, not shown, throughout a house or building, into which the terminals I4 may be inserted. By ccnnecting the terminals l4 within the female sockets of the ordinary wall-mounted receptacle, the usual male terminal prongs of an electric light fixture or appliance may thereafter be inserted within the sockets ill of the end member 9 for electrical engagement with the contacts i2. Upon closure of a switch 23 which is normally associated with the electrical lighting appliance, which carries an incandescent lamp bulb 24, current is caused to flow through the resistance elements It to initially decrease the voltage passing to the filament of the lamp 24, whereupon the filament will glow with a subdued light and thereafter progressively increase in intensity with an increase in temperature of the resistance elements 18. By properly proportioning the resistance of the elements I B in association with the wattage of the incandescent lamp 24, the time required for an increase in illuminating power of the lamp 24 from a relatively light glow to substantially its full intensity may be Varied in accordance with the desires of the user. In this connection, I have found it advantageous to employ a total resistance which will enable the incandescent lamp 24 to attain approximately per cent efficiency in approximately one and onehalf minutes after closure of the control switch 23 and initial energization of the operating circuit for the lamp. In this manner, a room to be illuminated by the lamp 24 is not thrown into sudden brilliant illumination upon closure of the switch 23, but is lighted gradually with an increase in intensity by nature of the varying resistance of the elements [8.

Also, due to the initial decrease in voltage passing to the filament of the lamp 24, the same is protected against shock due to an otherwise sudden surge of operating current to the filament of the lamp upon closure of the switch 23. In this manner, the life of the lamp 24 is materially increased over similar lamps which are subject to immediate current flow upon energization of its operating circuit.

The outer casing 6, which is preferably formed from a high heat conductivity metal, such as copper, which enables heat emanating from the re sistance elements 58 to be quickly and rapidly dissipated from the receptacle, and due to its perforate nature, free circulation of air may be had through the receptacle to further reduce the temperature thereof,

In View of the foregoing, it will be seen that the present invention provides a unique and useful auxiliary electrical receptacle for use in connection with electrical lighting appliances to initially reduce the degree of illumination of an associated incandescent lamp bulb upon energization of the operating circuit therefor, but which, following initial energization,' permits the bulb to attain substantially maximum illuminating power. Thus, use of the present receptacle in connection with an electric lamp results in an eflicient and safe night lamp for use in bedrooms or bathrooms of a home to prevent the damaging effect of immediate illumination of a darkened room to a person awakening from sleep.

While a preferred embodiment of the invention has been disclosed in detail, it will be under stood that various modifications as t construetional details is comprehended without depart ing from the spirit of the invention or the scope of the following claims.

I claim:

1. An auxiliary receptacle for electrical lighting appliances comprising a receptacle frame provided at one end with a dielectric member defining socket means for the reception of the male terminals of an electrical lighting appliance; a pair of electrical contacts positioned in said socket means for circuit-making engagement with the male terminals of an electrical appliance received therewith and thereafter to progressively increase said voltage to cause the lighting appliance to progressively increase in illumination following energization thereof.

2. In an auxiliary electrical receptacle for electrical lighting appliances; a receptacle body provided at opposite ends with dielectric members one of said members defining socket means for the reception of the male terminals of an electrical lighting appliance; a pair of electrical contacts positioned in said socket means in relatively spaced non-shorting relation and arranged to engage the respective male terminals of an electrical lighting appliance inserted in said socket means; a pair of male terminals carried by and projecting outwardly from the other of said dielectric members and disposed in relatively spaced non-shorting relation; conductor means electrically connecting one of said contacts with one of said male terminals; and an electrical resistance element having a negative coefiicient of resistance connected between the other of said contacts and the other of said male terminals for initially decreasing the voltage passing through said receptacle to a lighting appliance connected therewith and thereafter to progressively increase said voltage to cause the lighting appliance to progresively increase in illumination following energization thereof.

' 3. An electrical receptacle for electrical light ing appliances comprising a receptacle body provided at one end with socket means for the reception of the male terminals of an electrical lighting appliance and at its opposite end with a pair of male terminals for electrical connection with a source of electrical energy; conductor means electrically connected between said socket cans and said terminals; and electrical resistance'means electrically connected with said conductor means and contained in said receptacle body and having a negative temperature-resistant coefficient, said receptacle being adapted to be connected between a lighting appliance and a source of electrical energy, and said resistance means serving, upon energization of the lighting appliance, to initially reduce the voltage for the appliance and thereafter to progressively increase the voltage to substantially the maximum voltage of said source.

ROGER A. McARRON.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,609,055 MacBooth Nov. 30, 1926 2,375,497 Scully May 8, i945 

